Roof mount exhaust fan vs wall mount on sides of food truck

Why do most of the food trucks and trailers have roof-mounted exhaust fans compared to many of the trucks "out west" with side-wall mounted exhaust fans? Is there any rules in Florida that specify which fan you can have?

You need to check with your local officials to find out what they will or won't allow. Don't go by what someone reports online, you'll only get their interpretation of the local rules.

But that said you always need to watch your overhead height. If your over 14 - 6 you can't drive under an interstate overpass. And in the north there are many overpasses in and around cities that are lower than that. So if your truck is too tall your going to knock off the exhaust system fan and destroy at least part of your roof.

that would be my #1 reason for having a wall exhaust, i dont really see any difference in the functionality between the two, other then the wall mount looks a million times better over having that big stupid looking stainless ice cream cone sticking out the top..... but like said, its best to check and see what they will accept, HD's arent known for being realistic when rules are set forth.....never know what kind of quirky little rules they have in your area

Again it's your local authority......... in Illinois the fire marshal has nothing to do with restaurants or the inspection process. It's health Department, Local Fire Department and the Zoning Department.

Id call my local fire departments non emergency number and speak with them first. You'll find the lower on the totem poll easier to deal with in most cases.

If I had my druthers .... I would mount on the side wall if possible. ... Because (other than height) it would be allot easier to clear condensate grease off the wall without getting on the roof. Just pull though a car wash and put a couple of quarter in the jet sprayer.

I dont believe the h/d has a druther on roof vents,or side mount. in my area it's the fire marshall, but as the dr. said better check with your area. my roof mount has a "drain" sorta on the side every once in a while i have to do just like edwmax say's car wash and pressure wash the side... most generally when I forget to wash the filters often enough...

Lee... I will have two fryers and a range under my hood. The range has two burners and a 24" griddle. The pictures that I've seen have three fans on the wall compared to one duct going up out one exhaust fan. Based on CFM calculations I need 1750 CFM exhaust fan. How does that convert to multiple wall mount fans?

I have the vertical exhaust on my trailer, it will suck the frp off the walls if left on without an air source. I have also worked on trucks with the horizontal exhaust, 3 and 4 fans. No comparison. It is a much cleaner look, but not efficient.

Two options: Bad idea & Bad idea the three fans are need to make up the cfm requirement...Lets say you need 900 cfm by calculations each fan moving 300 a piece ... not engineered well IMHO. Why not have a bigger motor with variable speed? Vertical fans move more air easier. Look at maintenance alone on three motors, cost to run, efficiency, more surface to clean , cost for each motor...list is too long!

Chefbuba...define "not efficient". I will have a 7ft wide by 18ft box with 8ft in windows and a rear door and a 13,500 RV AC unit. My hood will be 7ft wide so I was thinking 3 fans because it is clean like you say. Are these fans not powerful enough to pull out the vapors?

Chefbuba...define "not efficient". I will have a 7ft wide by 18ft box with 8ft in windows and a rear door and a 13,500 RV AC unit. My hood will be 7ft wide so I was thinking 3 fans because it is clean like you say. Are these fans not powerful enough to pull out the vapors?

First: CFM is still CFM. If the air flow is powerful enough to suck the frp off the wall blowing vertical, it would still be powerful enough to do the same blowing horizontal. ... I have an idea someone is not comparing apples to apples.

Second: The exhaust fan on a vent hood will be inline (in the duct) or at the end of the duct (the roof or side wall ventilator). ... The use of 3 fans would indicate these are not sucking through the vent hood exhaust duct. ... 3 wall mounts exhaust fans will defeat the purpose of the hood. But, they can ventilate the trailer and the hood would be just for looks. ... So where and how are the 3 fans to be mounted in relation to the cooking line & hood?

Third: The size you gave for the trailer is 7ft X 18ft & assuming 8ft ceiling ht, the trailer volume is 1008 cft. ... The exhaust for vent hoods are usually based on a 'rule of thumb' of 100 to 300 cfm per foot length of hood; with 200 cfm being for medium heat kitchen commercial equipment. ... Another 'rule of thumb' is to exhaust 100 cfm of air per every 10,000 BTU of heat. You haven't gave BTU size of your Equipment ... You have a small size trailer compared to a commercial kitchen; ... the difference being other air currents that effect the air flow of the hood which would or should not exist in your trailer. So I think you only need to use an exhaust rate of 100 cfm per of hood. .... a 7ft hood @ 100 cfm => 700 exhaust air. Cross check this calculation with the Total BTU size of the cooking equipment. ... At this rate the trailer will completely change air every 1 3/4 minutes. ... Since the AC will not cool this amount of air, keep the window open (or door) so the air flow will cool you while working.

edwmax keep the window open (or door) so the air flow will cool you while working.

And don't let the health department in most states catch you with a service window or door open because they will throw a fit. However in some of the states they will allow you to cook open air. So again like always you need to check with your local H.D. on every thing. We need an acronym for that so it doesn't have to be spelled out constantly. CYLHD!

edwmax keep the window open (or door) so the air flow will cool you while working.

And don't let the health department in most states catch you with a service window or door open because they will throw a fit. However in some of the states they will allow you to cook open air. So again like always you need to check with your local H.D. on every thing. We need an acronym for that so it doesn't have to be spelled out constantly. CYLHD! Jack

Then you need screens, as the air has to flow; or other screened side wall vents for air intake (hummm ... a window???).

nope, you need 1300 or over.. cfm wise. and yes it sucks the tile flooring up and eveything else out .

yep ... that's at abt. 200 cfm per ft of hood. The rule of thumb most people use. ... But the actual air exhausted should be checked using the total BTU of the cooking equipment. ... May need more; ... may need less.

That totals about 259,000 BTU if every thing is running at one time wide open. I think you would be running about 1/3rd of that as average. 2600 CFM exhaust in that small trailer is almost 3 air changes per min and would feel like being in a tornado. A 1/3 of the 2600 would be 1200 cfm exhaust. a variable speed fan (3 speed) wouldn't be a bad investment to allow an exhaust range of abt 600 to 1400 cfm depending on heat & smoke.

That totals about 259,000 BTU if every thing is running at one time wide open. I think you would be running about 1/3rd of that as average. 2600 CFM exhaust in that small trailer is almost 3 air changes per min and would feel like being in a tornado. A 1/3 of the 2600 would be 1200 cfm exhaust. a variable speed fan (3 speed) wouldn't be a bad investment to allow an exhaust range of abt 600 to 1400 cfm depending on heat & smoke.

Ok so now what? I haven't been able to find an exhaust fan between 1000 and 1700 cfm. Look at trucks like nom nom, grill em all, and other trucks and none of them have the big exhaust fan on top of the trucks. I talked to the state today and they have no rules regarding exhaust fans. They are reviewing my plan and have told me to talk to the fire marshall.

EDWMAX...CFM is CFM your right and thats where it stops..but that was not the question... There are lots of factors in CFM with equivalent horsepower in doing a comparison...air density, position of the fan motor alone changes the performance tremendously with respect to resistance to flow....sq ft of area vs duct size...pressure...the list is huge sorry apples to apples doesn't apply here. Im not the expert by any means just years of building.... from Jail Cells to houses and everything in between.

EDWMAX...CFM is CFM your right and thats where it stops..but that was not the question... There are lots of factors in CFM with equivalent horsepower in doing a comparison...air density, position of the fan motor alone changes the performance tremendously with respect to resistance to flow....sq ft of area vs duct size...pressure...the list is huge sorry apples to apples doesn't apply here. Im not the expert by any means just years of building.... from Jail Cells to houses and everything in between.

Now you are talking 'fan, piping & system design' all the components that has to be taken into consideration to deliver a required CFM of a fan and the require power (horse power) to do so. If you look at the fan ratings it will give you the fan CFM at certain resistance pressure (water column ???). ... CFM is not where it stops, but rather where the system design starts!

browe, This website has up blast exhaust fans from 860 CFM (3/4 hp), 1575 CFM (1/2 hp) and up. .... Although, I don't think I would use the up blast style because of it height. Than fan and the motor is contain within the external housing.

Try to visit other food trucks or trailer in your area; see what they did and ask how they like the hood & fans.

A while back I saw a suppler for twin electric (12v) auto fans abt $150 (???). These could work in a wall mount with a transition air box to the hood piping; and a simple external louver.

No one who knows anything about exhaust systems would ever recommend the following:

"A while back I saw a suppler for twin electric (12v) auto fans abt $150 (???). These could work in a wall mount with a transition air box to the hood piping; and a simple external louver. "your kidding right" ?BROWE...do yourself a favor talk directly with a manufacturer about their product. Have the following on hand: Your sq footage of the unit, fresh air intake sq ft available (windows/doors that will remain screened & open) and total BTU that is present. They do the math and calculate the proper exhaust fan you need it will be right and you will not be sorry.